The phrase "hammerhead shark" is used to describe a group of sharks in the Sphyrnidae family.
There are at least nine known species of hammerhead sharks.
The known nine species of hammerhead sharks are the bonnethead (Sphyrna tiburo), Carolina hammerhead (Sphyrna gilberti), great hammerhead (Sphyrna mokarran), scalloped bonnethead (Sphyrna corona), scalloped hammerhead (Sphyrna lewini), scoophead (Sphyrna media), smalleye hammerhead (Sphyrna tudes), smooth hammerhead (Sphyrna zygaena) and winghead shark (Eusphyra blochii).
Hammerhead shark species can be as short as 3 feet and as long as 19.7 feet.
Hammerhead shark species can weigh as little as 6.6 pounds and as much as 1,300 pounds.
Hammerhead sharks are carnivores.
Hammerhead sharks can be found in warm waters worldwide.
Hammerhead sharks travel in schools during the day time and hunt alone at night.
While they are one of the most feared type of sharks there has never been a recorded human fatality by any species of hammerhead sharks.
The IUCN lists the conservation status of the great and scalloped hammerhead as endangered.
The IUCN lists the conservation status of the smalleye hammerhead as vulnerable.